Affordable Robots in Environmental Science

Post by: Dong
Yoon Lee

Email:
dolee@fiu.edu

Let me start with some questions. Have you ever lost all of your samples in a freezer because of a power outrage? Have you made your family unhappy
(or happy) because you spend more time with laboratory rats? Have you failed to
collect soil samples after a long boat trip because of unpredicted high water
levels? Have you found out that super high phytoplankton production was caused
by your advisor accidentally turning on a light during dark cycles?

It is not uncommon to hear these kinds of unfortunate events
from fellow scientists. It seems almost inevitable for biologists to avoid them
because nature is full of surprises and that’s why we love studying biology! But
wouldn't it be nice if you had a robot preventing unwanted events from happening? In
addition, wouldn't it be even better if a robot was easy to program, to make, and most importantly, affordable. We tend to think that a robot is an intelligent
object with arms, legs, or at least blinking eyes like the Disney character "Wall-E".
But the definition of robot on Wikipedia is rather simple: “A robot is a
machine… capable of carrying out a complex series of actions automatically.” Thanks
to a boom of open-source platforms, we can make a robot under $10.

You may have heard about open-source platforms, which are freely
available and sometimes supported by thousands of users who are willing to improve them by fixing bugs or adding features. For example, R Studio is an open-source
computing software. But we need an electrical platforms (i.e., computer) to build
a robot. Let me introduce a small, light, affordable, powerful, and new
generation computing platform called Arduino (Fig. 1).

Arduino is an open-source micro-computer that can read
inputs and send outputs. For example, a combination of Arduino with a sensor
and a communication device can detect a change (input), activate a physical
device (output), and report programmed messages on the web, email, your phone,
or Twitter (output). If you can make a formula on Excel, you are coding already.
To help you understand the function and capability of Arduino, I will share my
recent project below (Fig. 2):

·Project: Chloe’s
pulse monitor

·Purpose: I want
to examine Chloe’s heartbeat in response to the sight of different objects such
as a treat or a cat. Her pulse will be continuously collected on the cloud
service and analyzed for detecting an unusual pattern of Chloe’s pulses. If her
heartbeat is unusually high, I want to be notified remotely.

Fig 2. Chloe’s pulse
monitoring methods and results. Left: Pulse sensor is attached to Chloe’s chest
and connected to a Wi-Fi-enabled micro-controller. Right: Screenshot of a code
which is uploaded to the micro-controller via Wi-Fi.

Chloe’s pulse turns out to be a reliable variable to measure
her status/conditions (Fig. 3). When I showed her a chicken treat (the first
peak), her pulse went up and dropped rapidly within 40 seconds. When she saw a
cat (the second peak), her pulse went up and dropped gradually for more than 2
minutes. Indeed, the sight of a cat infuriated Chloe so much that Chloe spit out
the treat and almost ran into the window! If I have more data and can find a
correlation between pulse patterns and her behaviors, I would be able to tell more
about Chloe’s status/conditions remotely. Can you think of other applications
with the same robot? What other sensors would you add to monitor new variables?
What other communication methods would be appropriate for different purposes (e.g.,
radio frequency, Bluetooth, Wi-Fi, Telephone system (SMS), or Internet (TCP/IP))?

Fig 3. Chloe’s pulse monitor.
Left: Her pulse is collected and reported on Thingspeak cloud service every 20
seconds. Note the differences in the magnitude and duration of high pulses
after she saw a treat and a cat. Right: Every time her pulse goes higher than
700 (unitless) for more than 1 minute, IFTTT service sends a notification on my
phone.

I have used a series of micro-controllers and
off-the-shelf electronics (e.g., pumps, valves) to simulate saltwater intrusion
in natural wetlands (Fig. 4). A waterproof ultrasonic distance sensor is used
to measure water levels in the creek where the main pumps are located. Creek
water is delivered into water tanks and pre-made brine water is delivered into
one of tanks to prepare brackish water every high tide. During low tide, the
water is gravity-fed through solenoid valves and meters out to each plot. The
entire system consists of 5 pumps, 10 solenoid valves, 2 flow meters, 4
sensors, solar panel, 3 large tanks, and Arduinos at a cost of $1800 (Lee et
al. 2016. Link: http://link.springer.com/article/10.1007/s13157-016-0801-4). Not bad price, isn’t it?

Fig 4. Left: The PVC manifolds
and electronics layout inside the weatherproof box. Middle: I was carrying the
brain of the system in a waterproof box. Right: Experimental plots laid out in
two rows with the platform containing the holding tanks and electronics in the
center.

I like to finish with an inspiring quotation: “Logic will get
you from A to B. Imagination will take
you everywhere.” If you can build a robot, you will be able to test almost
anything you can imagine. Happy making!

‘Who’
is it and where does it live? This
centric diatom’s cells are drum-shaped, the valve diameter and the density of marginal striae are highly
variable. Cyclotella meneghinianais a rather cosmopolitan
species; in tropical freshwaters,it is associated with various
water depths and salinity1, and, in temperate regions, it is a
typical planktonic taxon in the late summer-autumn2. In North America, this species can cope with a wide range of conditions, for
example from freshwater to saline waters in the Great Plains lakes3.
a) b)

Why
are we studying it? Studying the distribution of this and other
diatoms in thousands-of-years old sediment and ice cores, paleoecologists - nature’s ‘archaeologists’ - can infer past
salinity, pollution, eutrophication and climatic changes4. Moreover,
analyzing water, soil and vegetation…

‘Who’
is it? The genus Gomphonema includes numerous species growing on mucilaginous stalks. These
diatoms are asymmetrical biraphid, as the bottom
part is usually longer and thinner than the top part and they have two raphes, narrow
slits that allow them to move over surfaces. Yes, there are diatoms that perform photosynthesis, move
and even eat
organic matter! G.
parvulum is on the lower end of the size spectrum for the genus (length
from 15 to over 100 µm and width between 5 and 15 µm).

Where
does it live? In North America, species of Gomphonema can be found in
many habitat types in lakes and streams with pH close to 7. Gomphonemaparvulum is widespread and tends to live in
freshwater with high nutrient concentrat…